Uzhhorod National University

About: Uzhhorod National University is a education organization based out in Uzhhorod, Ukraine. It is known for research contribution in the topics: Raman spectroscopy & Laser. The organization has 1089 authors who have published 1056 publications receiving 5187 citations. The organization is also known as: State Higher Education Establishment "Uzhhorod National University" & Uzhhorod State University.

Low-pressure glow discharge in a Xenon/Chlorine mixture

Abstract: The spatial, electrical, and optical characteristics of a transverse glow discharge and a volume discharge with a spherical anode and plane cathode in low-pressure Xe/Cl2 mixtures are studied. It is shown that the transverse glow discharge in mixtures with a low chlorine content occupies most of the interelectrode gap and exists in the form of strata. As the total pressure (P≥300 Pa) and the partial chlorine pressure (P(Cl2)≥80 Pa) increase, a solitary plasma domain with a volume of 1–2 cm3 forms in the discharge gap. It acts as a selective source of UV radiation in the XeCl(D-X) 236-nm, Cl2 (D′-A′) 257-nm, and XeCl(B-X) 308-nm bands. In certain Xe/Cl2 mixtures, plasma self-oscillations in the frequency range 1–100 kHz are observed. The current of a low-pressure volume discharge with a spherical anode and plane cathode and the emission from it have both a dc and an ac component. The pressure and composition of the working mixture, as well as the average current of the volume discharge are optimized to attain the maximum emission intensity of the XeCl(D,B-X) bands. Low-pressure volume discharges in xenon/chlorine mixtures can be used as active media in low-pressure large-aperture planar or cylindrical excimer-halogen lamps emitting modulated or repetitive pulsed UV radiation.

Dielectric Properties of Cu(In0,7Cr0,3)P2S6 Crystals under High Hydrostatic Pressure

Abstract: Composition and dielectric properties of Cu(In0.7Cr0.3)P2S6 crystals have been investigated in the temperature range 77 < T < 450 K under hydrostatic pressure (0,1 < p < 500 MPa). At temperatures above 300 K, we observed frequency dependent anomalies of real and imaginary part of dielectric permittivity. The (p,T) phase diagram of Cu(In0.7Cr0.3)P2S6 crystals has been constructed.

Detection of breast cancers represented as architectural distortion: a comparison of full-field digital mammography and digital breast tomosynthesis.

Abstract: Objective The aim: The aim of our study was to determine if digital breast tomosynthesis improves breast cancer detection associated with architectural distortion in comparison with full-field digital mammography in the absence of appropriate history of trauma or surgery. Patients and methods Materials and methods: The overall rate of breast cancer involvement for the 34 patients with architectural distortion was 15 cases (44,1%) (invasive breast cancers, n=12 (36,4%); ductal cancer in situ, n= 3 (8,8%)) other findings associated with architectural distortion were high-risk lesions and benign findings (radial scar, n=5 (14,7%); sclerosing adenosis, n=9 (26,5%); typical lobular hyperplasia, n=3 (8,8%); typical ductal hyperplasia, n=2 cases (5,9%)). Results Results: Overall of 17/34 (50.0%) architectural distortions were identified at digital breast tomosynthesis that were missed at full-field digital mammography what was statistically significant difference ([95% CI, 2.56-7.45]; p=0.00001). Analysis of the results showed that sensitivity of full-field digital mammography for digital breast tomosynthesis detected breast cancers associated with architectural distortion was 53.3% [95% CI, 26.59% to 78.73%] and specificity was 52.63% [95% CI, 28.86% to 75.55%]. Conclusion Conclusions: Our study suggests that digital breast tomosynthesis detects more breast cancers represented as architectural distortion which are occult on full-field digital mammography. Presence of microcalcifications within architectural distortion, in the absence of appropriate history of trauma or surgery, has a high likelihood of malignancy and obligatorily requires biopsy.

The formation of excited chlorine atoms in a low-pressure transverse volume discharge

Abstract: The characteristics of a transverse volume discharge (TVD) in chlorine at low pressures (P(Cl2)=0.1–1.5 kPa) were studied. The excited chlorine atoms were formed in a 18×2.2× (0.5–1.0) cm volume using relatively low values of the capacitor bank charging voltage (Uch ≤ 10 kV) in the pulsed discharge voltage source. The optical emission from plasma was studied in a spectral range from 500 to 900 nm. Homogeneous TVD pulses of short duration (τ; ≤ 100 ns) obtained under these conditions are of interest for use in UV-VUV lamps employed in pulsed plasmachemical reactors for dry etching of thin films. The density of excited atomic chlorine radicals can be monitored on medium-resolution spectrometers using the ClI emission lines with λ=725, 754, and 821 (2) nm.